Forum Discussion
Outlook on smartphone issue
- Yes, it's correct, you always have to point to the autodiscover on the On Prem server. In fact, Outlook for mobile uses Microsoft servers to resolve client autodiscovery. It is not the mobile which makes the discovery.
You need to open the IP from Microsoft to your On Perm Exchange server for accept connection with Outlook for mobile.
IP List :
https://learn.microsoft.com/en-us/microsoft-365/enterprise/urls-and-ip-address-ranges?view=o365-worldwide
When you can confirm the connection with https://testconnectivity.microsoft.com/tests/Eas/input you can use Outlook.
Outlook for mobile does not connect directly to the On Perm Exchange server but from a Microsoft server, this proxy connection is supposed to come from a geographically close Microsoft server.
So you are confirming the Outlook for IOS DOES require external connectivity, even if the activesync url should be resolved with internal server IP ?
The customer has a specific configuration in which the Smartphone APN is allowing the devices to be directly connected to internal network and resolve fqdn from internal DNS.
Is there a KB or microsoft article I can look at and share with the customer ?
thanks
Yes exactly. Because Outlook goes through Microsoft servers to query autodiscover. This does not depend on Active Sync. Other applications like Mail, Android Mail which use their own autodiscovery questioning system allow you to connect with ActiveSync without problem, which is not the case with Outlook for Mobile.
- Thierry_Chapuisat
As far as I know Autodiscover url, even in hybrid configuration, should always point to the Customer's On-Premise "public" IP address so it sound strange that "outlook form mobile" would search autodiscover in "microsoft's server" since they cannot for sure know nothing about the on-premise setup.- Yes, it's correct, you always have to point to the autodiscover on the On Prem server. In fact, Outlook for mobile uses Microsoft servers to resolve client autodiscovery. It is not the mobile which makes the discovery.